1. Field of the Invention
The present invention pertains to a freewheel unit which is intended especially for the stator of a hydrodynamic torque converter and which allows two elements to rotate with respect to each other around an axis of rotation in essentially only one direction.
2. Description of the Related Art
Freewheel units of this type are used, for example, to connect the outer area of the stator in a hydrodynamic torque converter to a support element such as a support shaft. Through the use of these types of freewheel units, it is ensured that the stator or the area of the stator which carries the vanes is supported so that it can rotate in one relative direction while being prevented from rotating in the other direction.
WO 91/16553, for example, discloses a freewheel with a plurality of pawls which are carried on one of the two elements which can rotate relative to each other, and are free to pivot. The pawls have locking sections which can come to rest against blocking surfaces on the other elements when these other elements try to rotate in the blocked direction. It is also known that ball elements can be used to produce a wedge-like blocking action when the two elements try to rotate with respect to each other in the unallowed direction of relative rotation.
All these freewheel units consist of a large number of separate elements, which must be put in place individually during the assembly process. This means that a great deal of work is required to produce such units.
It is the object of the present invention to make available a freewheel unit which is intended especially for use with the stator of a hydrodynamic torque converter and which is of simple design but nevertheless offers a reliable blocking action.
According to the invention, the freewheel unit allows two elements to rotate relative to each other around a rotational axis essentially in only one direction. This unit includes a locking element carrier, extending in the circumferential direction around the rotational axis, and at least one locking element, which is carried on the locking element carrier and which extends away from this carrier in a first circumferential direction and toward a first side, where at least one blocking surface is provided on the first of the two elements, against which at least one locking element can come to rest to prevent any relative rotation between the first element and the locking element carrier in one direction of relative rotation.
In the freewheel unit according to the invention, therefore, the locking element carrier, which carries at least one locking element, is offered as a complete assembly, so that the work of inserting a plurality of separate locking or latching elements and fastening them in place is no longer necessary.
So that the freewheel unit according to the invention can provide a similarly reliable blocking function with respect to the second of the two elements, this unit also comprises at least one second locking element, which is carried on the locking element carrier, and which extends away from the carrier in a second circumferential direction essentially opposite the first circumferential direction and toward a second side essentially opposite the first side, where at least one second blocking surface is provided on this second of the two elements, against which at least one second locking element rests or can come to rest to prevent any relative rotation between the locking element carrier and the second element in one direction of relative rotation. In this case it is also advantageous for the first blocking surface, of which there is at least one, and the second blocking surface, of which there is also at least one, to be freely exposed so that they can interact with the first locking element, of which there is at least one, and the second locking element of which there is also at least one, in essentially opposite circumferential directions.
So that the load can be distributed uniformly in the circumferential direction during the transfer of torque, it is proposed that first and second locking elements be provided in alternation with each other in the circumferential direction on the locking element carrier. To prevent any undesirable or undefined shifting in the position of the locking element carrier, furthermore, it is also especially advantageous for this carrier to be fastened to one of the two elements.
A highly reliable locking effect can be obtained by designing the locking element carrier essentially in the form of a ring. For example, it is possible to provide a locking element carrier which is essentially in the shape of a cylinder or a section of cylinder, from which the first locking elements extend away radially toward the outside. It is in this case also advantageous for the second locking elements to extend away from the locking element carrier radially toward the inside.
In an alternative design, it is possible to provide a locking element carrier which is essentially in the form of a ring-shaped disk or section of a ring-shaped disk, from which the first locking elements extend toward a first axial side. In this type of design, it is then possible according to the invention to provide in addition that the second locking elements extend away from the locking element carrier toward a second axial side essentially opposite the first axial side.
So that the constructive design can be simplified even further, it is proposed that the locking element carrier be made of sheet metal together with the locking elements, which are formed as integral parts of the carrier. It can then also be provided that the first locking element, of which there is at least one, and/or possibly the second locking element, of which there is also at least one, are bent away from the locking element carrier toward the first and second sides, respectively,
The present invention also pertains to a hydrodynamic torque converter which has a freewheel unit according to the invention, where a plurality of guide vanes is supported on the radially outside area of the first of the two elements, and where the second of the two elements is supported nonrotatably with respect to a support element.
It can also be provided that the first element is supported on the second element so that it is free to rotate in the axial direction and/or in the radial direction.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.